1. Field of the Invention
This invention relates to a fuel injection device of a diesel engine and more particularly to a control system of a rack position by a governor.
2. Background Art
In starting the diesel engine, the amount of fuel injection is typically increased for the start ability by making a starting fuel amount position of the rack in the fuel injection pump shifted to an increased starting fuel amount position. Providing enough amount of fuel to the engine keeps the start ability without considering the environment of the engine.
FIG. 24 typically illustrates a conventional starting process of the engine. It is operated in the order, (a), (b), and (c) in FIG. 24. The left part of FIG. 24 illustrates a situation of the fuel injection pump. The center part of FIG. 24 illustrates a situation of a starter motor 32. The right part of FIG. 24 illustrates a relation between the rack position and the elapsed time.
As shown in FIG. 24, an electronic governor 41 controls the amount of fuel injection of the fuel injection pump 34; in this case, the amount is zero until the engine starts. When the starting switch is turned on, the rack is operated to a starting increased fuel amount position and the starter motor cranks up the engine. The electronic governor operates the rack to the position before the starter motor finishes cranking, and enough amount of fuel corresponding to the starting increased fuel amount position is supplied to cylinders of the engine 1.
Japanese patent application H5-321699 discloses, for example, that the electronic governor adjusts the amount of fuel injection according to the temperature of the engine oil.
However, the larger amount of fuel than the is sufficient is supplied to the engine when the starter motor cranks up the engine. Therefore, the fuel consumption becomes higher in starting the engine, and surplus fuel may cause black smoke.
In the art, enough amount of fuel for starting the engine is supplied at the beginning and the fuel supply tends to become higher, so that the fuel consumption for starting the engine becomes higher.